Molding machine



March 2,0, 1945.

P. PRITCHARD MOLDING MACHINE Filed May 8, 194? 2 vSheeT--Sheet 1 March 20, 1945. P; PRITCHARD MOLDING MACHINE Filed May s, 1942 2 Sheets-Sheet 2 MMT.

|||||||||||||||||||| Illlr Mvr cullill Sw.;

lllllll ll llllllllllllLlllllll 111.0

Izar/elo of Jpefclz/ fr@ 'ZCfa Patented Mar. 20, 1945 reo fs'rlr'resv PATENT office- I l MoLmZ-ilrsliicnmn l y l I Percy Pritchard, Wootton lWawen,Eng1and Appucation'may fsf, j1942,"seria;1"Nn. '442;187

`In 'Great 'Britain June 4, 19.41 .l

'3 Claims. (Cl. T22-1455) This lnvention'relates `to improvements in molding machines .of the type Ain which a mold 'to `be rammed Aisplaced on va vertically movable table which is jarred by 4a 'pneumatic cylinderor ram.

In suchmachines it :is desirable that .the table should be effectively guided in its vertical reciprocating movement as uniformity in the ramvery heavy-.loading and when wear takes place* there is `no effective means of adjustment. v

One object of my invention is to provide means whereby the table .is veffectively guided independently of the ram .and whereby adjustment of in machines .of this type.

the guiding :means to compensate for wear can be rapidly 'and easily effected without having to dismantle the machine so 'that the guiding of the table can be .kept uniform and accurate 'throughout lthe life of the'm'achine.

Other objects are to improve the functioning of the machine generally with a view to reducing wear and simplifying maintenance. I

According to one feature of my invention, in a molding machine of the type setforthabove machined vertical faces at each corner of the vertically `movable table co-operate with -complementary guiding surfaces or wearv plates on the base which are adjustable towards and away from the table by means accessible from the outside of the base to compensate for wear` and to allow the table to be guided smoothly and accurately with a minimum of friction.l

Alternatively the guiding surfaces or wear plates on the base may be xed while co-operating surfaces on the tables are adjustable.

One practical design of molding machine incorporating my invention is illustrated by way of example in the accompanying drawings in which:

Figure 1 is a side elevation in part section of the complete machine.

Figure 2 is a plan in part section.

Figure 3 is a fragmentary section on the line 3-3 of Figure 2, but modified to illustrate a separate wear plate mounted on the table.

Figure 4 is a fragmentary section on the line 4-4 of Figure 2, but modified to illustrate a separate wear plate mounted on the guide member.

The molding machine illustrated comprises a fiat table I adapted to receive a mold and vertically movable on a base II. The vertical movement of the table is effected in the ordinary way by the'admission of compressedfair 11o-centrally located vertical .ram cylinder I2 which is -carriedby the 'base and in which works a ram I'3`forming I part of the table.

The table is rais/ed by the 'compressed air and on release ofthe air the table is allowed to drop on to the base to jar and ram the mold, as is usual The impact is taken by a Vnumber of spaced bosses I 4 on the 'bottom of the table which engage .steelplungers "I'B'Ver'tically slidable in cylindricalr recesses .Ij6 Ilin the base, alhard rubberor othery resilient buffer f1 being arranged inthe bottom of 'each 4recess to produce .a bump which is dead solid and lfree from metallic shock and rebound. This method fof taking lthe impact distributesthe shock uniformlyover the whole area of thetable and 'ensures uniform density of ramming in the mold. 'The recesses I6 and the plungers I5 which work in them are. -made of considerable axial length to ensurev a truly vertical movement of the plungers `and yprevent any risk of vthe plungers jamming in the recesses. 4

To minimise transmission of the shock to the ground and to any surrounding plant a thick layer of vibration deadeningand absorbingmaterial I8 i is arranged between the base I I and a heavy subbase I9 on which it is mounted and which is set on a substantial concrete foundation.

'The table and the base `are stiifened by internal ribbing 20 and 2I. Excessive upward movement of the table on the base is prevented by vertical bolts 22 fixed in the base and extending through `slots in lateral flanges 23 on the table.

At each vcorner of the table below the upper surface there are two flat machined vertical surfaces 25, 26 extending at right angles to each other and these surfaces are engaged by and co-operate with complementary guiding surfaces 21, 28 on a member 29 which is adjustable in a, horizontal direction along a line bisecting the angle at the corner. For the' adjustment of the member 29 a stud 30 secured into the member and projecting outwardly from it in the line 0f adjustment extends through an abutment 3l `on the base and a nut 32 is screwed on to the stud outside the abutment.

A heavy helical spring 33 is fitted over the stud between themember 29 and the abutment and tends to urge the surfaces 21 and 28 on the member 29 inwardly against the guiding surfaces 25, 26

ening the nut 32. The member 29 is supported by a flange or flanges 34 at its upper end resting on a rib 35on the base which may be continuous with the abutment 3| for the spring. The member 29 is clamped in the correct adjusted position by means of b'olts 36 passing through slots in the flange 34 and through bosses 31 on the rib 35 on the base.

Locking and unlocking of the clamping bolts is effected by a spanner applied to nuts 38 on the bolts below the bosses 3l which are accessible through openings 3S in the base, the bolts being held against rotation by angular collars 40 keyed on the lower ends of the bolts and in sliding engagement with the base.

the four sets of guiding surfaces 21, 28 are'uiged inwardly by their springs 33 with equal pressureand automatically centre the table withrespect to the base and also centre Athe ram I3'on the' In an alternative arrangement the adjustable guide surfaces may be mounted on the table while the cci-operating surfaces on the base are xed, and as the carrying out of this modification will be obvious to any engineer it has not been illustrated.

I claim:

1. A molding machine comprising a stationary base, a mold-receiving table vertically movable on the base, means for movingthe table vertically, machined vertical surfaces at right angles to each other on the table adjacent each corner On slackening oi the clamping nuts 38 and ff: the adjusting nuts 32 at each corner of the table,

thereof a member carrying complementary vertical guiding surfaces adapted to co-operate with -the'surfaces on the table and mounted on the base adjacent each corner of the table, and means table accurately with respect to its cylinder l2.

Each adjusting nut 32 is then simply tightened,

by an equal amount to Withdraw the guiding surfaces 27, 28 suiiciently far against the action of the springs 33 to give the requisite Working clearance for the table between these surfaces and the surfaces 25, 26, and the clamping `nuts 38 are tightened to lock the members 29. The adjustment is thus extremely simple vto effect and can be carried out by a maintenance engineer as part of his ordinary routine work.

The surfaces 21, 28 may be integral parts of the members 29 as shown in the drawings or they may be formed by separate Wear plates secured for adjusting said member towards and away from the table in a direction along a line bisecting the angle at the corner of the table.

2. A molding machine comprising a, stationary base, a mold-receiving table vertically movable on the base, means for moving the table vertically, machined vertical surfaces at right angles to each other on the table adjacent. each corner thereof, a member carrying complementary vertical guiding surfaces adapted to co-operate with the surfaces on the table and adjustably mounted on the base adjacent each corner of the table, a stud secured in said member and projecting out wardly in a direction bisecting the angle at the corner of the table, an abutment on the base through which said stud extends, a compression spring on said stud between the member and the abutment, a nut screwed on the stud outside the abutment. and means for clamping the member to the base.

flange thereon resting on a rib on the base, and the clamping means comprise bolts passing through the flange and rib and accessible from the outside `of the base. l

PERCY PRITCHARD. 

